A general power (electronic) module is a device configured to control power and functions as a key component in a power electronic system. A power module used in an eco-friendly car recently getting attention, a renewable energy generator, and a new concept power grid such as a smart grid controls high power and thus necessarily results in high power consumption. The power consumption is converted mainly into heat energy which causes a high temperature within the power module.
The high temperature may cause degradation or instability in performance of the power module and also cause damage to or failure of the module. Further, since the high temperature is generated only in a place where power is concentrated, the distribution of heat within the power module is not even. Due to the heat generation problem, it becomes important to measure an accurate temperature and a thermal stress caused by heat generation in the power module. The thermal stress can be measured by measuring distribution of temperature or distribution of stress during heat generation.
However, if a temperature sensor is integrated in a semiconductor to measure a temperature and a thermal stress within the power module, an operation of the semiconductor may be affected or a fine process may be needed, which makes it difficult to perform a sensor process. There are a few cases where a temperature sensor is integrated in a semiconductor. However, in such a case, high processing cost may be incurred and the performance of the semiconductor may be affected, and the semiconductor is necessarily increased in size. Particularly, the effect on the performance of the semiconductor makes it difficult to widely use this method.
Accordingly, there is a need for a technology of measuring distribution of temperature of a power module or a thermal stress generated by heat within a semiconductor.
Meanwhile, the heat generation problem within the power module has become worse recently, and has been accelerating with the advent of high-power systems such as an electric car or a smart grid. Particularly, a thermal stress which is one of phenomena caused by heat of the power module may cause various problems such as destruction of the power module and generation of fatigue. However, a complicated three-dimensional structure of the power module and a composition of different materials including repeated conductor and insulator cannot provide a suitable solution to the thermal stress problem. As such, due to the heat generation problem, it becomes important to measure an accurate temperature and reduce a thermal stress caused by heat generation in the power module.
However, if a temperature sensor is integrated in a semiconductor to measure a temperature and a thermal stress within the power module, an operation of the semiconductor may be affected or a fine process may be needed, which makes it difficult to perform a sensor process. There are a few cases where a temperature sensor is integrated in a semiconductor. However, in such a case, high processing cost may be incurred and the performance of the semiconductor may be affected, and the semiconductor is necessarily increased in size. Further, a technology for reducing a thermal stress in a portion where heat is concentrated according to a measurement result of temperatures and thermal stresses within a power module tends to be developed actively.
Accordingly, there is a need for a technology of indirectly measuring and reducing distribution of temperature of a power module or a thermal stress generated by heat within a semiconductor.